Doa untuk Siswa SBBS yang akan berjuang di OSN SMP....

Alhamdulillah...
3 Siswa SMPN SBBS sampai di Pontianak kemarin malam (28 Juni 2012)
Esok dan Lusa mereka akan mengikuti Ujian OSN SMP...
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Semoga ALLAH SWT memberikan mereka Kemudahan dan Hasil yang terbaik dalam OSN 2012... Amin...

Kalender Pendidikan Tahun Pelajaran 2012/2013

Berikut adalah Kalender Pendidikan tahun Pelajaran 2012/2013
Semoga dapat bermanfaat...
Kalender Pendidikan 2012/2013

Discovery of Material With Amazing Properties

ScienceDaily (June 24, 2012) — Normally a material can be either magnetically or electrically polarized, but not both. Now researchers at the Niels Bohr Institute at the University of Copenhagen have studied a material that is simultaneously magnetically and electrically polarizable. This opens up new possibilities, for example, for sensors in technology of the future. The results have been published in the scientific journal, Nature Materials.

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The "8-armed candlestick" in this unusual image of the measurements is proof that the "walls" of the domains in TbFeO3 repel each other at certain temperatures and therefore lie at a fixed distance from each other. The signal from the "ordinary" chaotic domain walls would more resemble a fly swatter. (Credit: Niels Bohr Institute)

 

Materials that can be both magnetically and electrically polarized and also have additional properties are called multiferroics and were previously discovered by Russian researchers in the 1960s. But the technology to examine the materials did not exist at that time. It is only now, in recent years, that researchers have once again focused on analyzing the properties of such materials. Now you have research facilities that can analyze the materials down to the atomic level.
Surprising test results
"We have studied the rare, naturally occurring iron compound, TbFeO3, using powerful neutron radiation in a magnetic field. The temperature was cooled down to near absolute zero, minus 271 C. We were able to identify that the atoms in the material are arranged in a congruent lattice structure consisting of rows of the heavy metal terbium separated by iron and oxygen atoms. Such lattices are well known, but their magnetic domains are new. Normally, the magnetic domains lie a bit helter-skelter, but here we observed that they lay straight as an arrow with the same distance between them. We were completely stunned when we saw it," explains Kim Lefmann, Associate Professor at the Nano-Science Center, University of Copenhagen.
They were very strange and very beautiful measurements and it is just such a discovery that can awaken the researchers' intense interest. Why does it look like this?
Explaining physics
The experiments were conducted at the neutron research facility Helmholtz-Zentrum in Berlin in collaboration with researchers in Holland, Germany, at ESS in Lund and at Risø/DTU. They would like to get a general understanding of the material and with the help of calculations; and have now arrived at a more precise image of the relationship between the structure of the material and its physical properties.
"What the models are describing is that the terbium walls interact by exchanging waves of spin (magnetism), which is transferred through the magnetic iron lattice. The result is a Yukawa-like force, which is known from nuclear and particle physics. The material exhibits in a sense the same interacting forces that hold the particles together in atomic nuclei," explains Heloisa Bordallo, Associate Professor at the Niels Bohr Institute.
It is precisely this interaction between the transition metal, iron, and the rare element, terbium, that plays an important role in this magneto-electrical material. The terbium's waves of spin cause a significant increase in the electric polarization and the interaction between the ions of the elements creates one of the strongest magneto-electrical effects observed in materials.
"Through these results we found a new pathway to discover and develop new multiferroics," emphasize the researchers in the group. Now it is up to further research to determine whether this new effect could lead to new applications of these materials with the amazing physical properties.

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Story Source:

The above story is reprinted from materials provided by University of Copenhagen, via EurekAlert!, a service of AAAS.
Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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Journal Reference:

1. Sergey Artyukhin, Maxim Mostovoy, Niels Paduraru Jensen, Duc Le, Karel Prokes, Vinícius G. de Paula, Heloisa N. Bordallo, Andrey Maljuk, Sven Landsgesell, Hanjo Ryll, Bastian Klemke, Sebastian Paeckel, Klaus Kiefer, Kim Lefmann, Luise Theil Kuhn, Dimitri N. Argyriou. Solitonic lattice and Yukawa forces in the rare-earth orthoferrite TbFeO3. Nature Materials, 2012; DOI: 10.1038/nmat3358

Jawa Tengah Juara Umum Festival dan Lomba Seni Siswa Nasional (FLS2N) Tahun 2012

Untuk melihat dokumentasi Festival dan Lomba Seni Siswa Nasional (FLS2N) Tahun 2012 silahkan klik gambar di bawah ini.

 
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Researchers Estimate Ice Content of Crater at Moon's South Pole

ScienceDaily  — NASA's Lunar Reconnaissance Orbiter (LRO) spacecraft has returned data that indicate ice may make up as much as 22 percent of the surface material in a crater located on the moon's south pole.

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Elevation (left) and shaded relief (right) image of Shackleton, a 21-km-diameter (12.5-mile-diameter) permanently shadowed crater adjacent to the lunar south pole. The structure of the crater's interior was revealed by a digital elevation model constructed from over 5 million elevation measurements from the Lunar Orbiter Laser Altimeter. (Credit: NASA/Zuber, M.T. et al., Nature, 2012)

The team of NASA and university scientists using laser light from LRO's laser altimeter examined the floor of Shackleton crater. They found the crater's floor is brighter than those of other nearby craters, which is consistent with the presence of small amounts of ice. This information will help researchers understand crater formation and study other uncharted areas of the moon. The findings are published in Thursday's edition of the journal Nature.
"The brightness measurements have been puzzling us since two summers ago," said Gregory Neumann of NASA's Goddard Space Flight Center in Greenbelt, Md., a co-author on the paper. "While the distribution of brightness was not exactly what we had expected, practically every measurement related to ice and other volatile compounds on the moon is surprising, given the cosmically cold temperatures inside its polar craters."
The spacecraft mapped Shackleton crater with unprecedented detail, using a laser to illuminate the crater's interior and measure its albedo or natural reflectance. The laser light measures to a depth comparable to its wavelength, or about a micron. That represents a millionth of a meter, or less than one ten-thousandth of an inch. The team also used the instrument to map the relief of the crater's terrain based on the time it took for laser light to bounce back from the moon's surface. The longer it took, the lower the terrain's elevation.
In addition to the possible evidence of ice, the group's map of Shackleton revealed a remarkably preserved crater that has remained relatively unscathed since its formation more than three billion years ago. The crater's floor is itself pocked with several small craters, which may have formed as part of the collision that created Shackleton.
The crater, named after the Antarctic explorer Ernest Shackleton, is two miles deep and more than 12 miles wide. Like several craters at the moon's south pole, the small tilt of the lunar spin axis means Shackleton crater's interior is permanently dark and therefore extremely cold.
"The crater's interior is extremely rugged," said Maria Zuber, the team's lead investigator from the Massachusetts Institute of Technology in Cambridge in Mass. "It would not be easy to crawl around in there."
While the crater's floor was relatively bright, Zuber and her colleagues observed that its walls were even brighter. The finding was at first puzzling. Scientists had thought that if ice were anywhere in a crater, it would be on the floor, where no direct sunlight penetrates. The upper walls of Shackleton crater are occasionally illuminated, which could evaporate any ice that accumulates. A theory offered by the team to explain the puzzle is that "moonquakes"-- seismic shaking brought on by meteorite impacts or gravitational tides from Earth -- may have caused Shackleton's walls to slough off older, darker soil, revealing newer, brighter soil underneath. Zuber's team's ultra-high-resolution map provides strong evidence for ice on both the crater's floor and walls.
"There may be multiple explanations for the observed brightness throughout the crater," said Zuber. "For example, newer material may be exposed along its walls, while ice may be mixed in with its floor."
The initial primary objective of LRO was to conduct investigations that prepare for future lunar exploration. Launched in June 2009, LRO completed its primary exploration mission and is now in its primary science mission. LRO was built and is managed by Goddard. This research was supported by NASA's Human Exploration and Operations Mission Directorate and Science Mission Directorate at the agency's headquarters in Washington.
For more information on LRO and the Lunar Orbiter Laser Altimeter, visit: http://lunar.gsfc.nasa.gov

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Story Source:

The above story is reprinted from materials provided by NASA.
Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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Journal Reference:

1. Maria T. Zuber, James W. Head, David E. Smith, Gregory A. Neumann, Erwan Mazarico, Mark H. Torrence, Oded Aharonson, Alexander R. Tye, Caleb I. Fassett, Margaret A. Rosenburg, H. Jay Melosh. Constraints on the volatile distribution within Shackleton crater at the lunar south pole. Nature, 2012; 486 (7403): 378 DOI: 10.1038/nature11216 \

http://www.sciencedaily.com/releases/2012/06/120620141159.htm

Panduan dan Kisi-kisi OSTN Tingkat Jawa Tengah Tahun 2012

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Neutrons Escaping to a Parallel World?

ScienceDaily (June 15, 2012) — In a paper recently published in European Physical Journal (EPJ) C, researchers hypothesised the existence of mirror particles to explain the anomalous loss of neutrons observed experimentally. The existence of such mirror matter had been suggested in various scientific contexts some time ago, including the search for suitable dark matter candidates.

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Researchers hypothesize the existence of mirror particles to explain the anomalous loss of neutrons observed experimentally. (Credit: © Pix by Marti / Fotolia)

Theoretical physicists Zurab Berezhiani and Fabrizio Nesti from the University of l'Aquila, Italy, reanalysed the experimental data obtained by the research group of Anatoly Serebrov at the Institut Laue-Langevin, France. It showed that the loss rate of very slow free neutrons appeared to depend on the direction and strength of the magnetic field applied. This anomaly could not be explained by known physics.
Berezhiani believes it could be interpreted in the light of a hypothetical parallel world consisting of mirror particles. Each neutron would have the ability to transition into its invisible mirror twin, and back, oscillating from one world to the other. The probability of such a transition happening was predicted to be sensitive to the presence of magnetic fields, and could therefore be detected experimentally.
This neutron-mirror-neutron oscillation could occur within a timescale of a few seconds, according to the paper. The possibility of such a fast disappearance of neutrons -- much faster than the ten-minute long neutron decay -- albeit surprising, could not be excluded by existing experimental and astrophysical limits.
This interpretation is subject to the condition that the earth possesses a mirror magnetic field on the order of 0.1 Gauss. Such a field could be induced by mirror particles floating around in the galaxy as dark matter. Hypothetically, the earth could capture the mirror matter via some feeble interactions between ordinary particles and those from parallel worlds.

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Story Source:

The above story is reprinted from materials provided by Springer, via EurekAlert!, a service of AAAS.
Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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Journal Reference:

1. Zurab Berezhiani, Fabrizio Nesti. Magnetic anomaly in UCN trapping: signal for neutron oscillations to parallel world? The European Physical Journal C, 2012; 72 (4) DOI: 10.1140/epjc/s10052-012-1974-5